Adhesive wrapping tape



. to protect.

Patented May 13, 1947 ADHESIVE WRAPPING TAPE Orvis H. Leidy, Grosjs e Pointe Mich assignor to Michigan Chrome & Chemical Company, 7 Detroit, Mich; a corporation of Michigan attractant 9,1945, saamltoaass This invention relates generally "to protective electrolytic or dielectric coating materials. More particularly, it relates to a novel and improved form of dielectric tape primarily designed and: intended for use in electroplating or electrolytic operations.

While the primary use of ta for other similar purposes in connection with the elcctrodeposition oi metals and electrolytic pickling and cleaning operations.

Since the function of electrolytic protective s or materialsof this general category is for masking electroplatinglracks, it will be readily appreciated that the I improvementsofth'e present ,inveriti'on, williind utiilty in the, masking, of parts to be plated ,and 1 sile strength, thereby permitting easy application, tight wrapping oi the portions of the parts coatings of the general character to'which the present inventionrelates is tomask or coat portions of aniarticle or element to be submerged in an. electrolyticbath, it is of primary importance that the coating appliedefiectively cover and sea-l those portions of the article which'it is desired present invention; contemplates the provision oi an electrolytic coating material in the. form pi e substantially homogeneous, resinous, ,ribbonlike;

In order to accomplish this, the

range] from high acid baths to Stilliurther, the present invention conternr plates the provision of an electrolytic coating which, when applied, not only has high dielectric strength, but which inherentlyprovides a relativelywsmooth, glossy coating. This .feature is important as in electrolytic operations it allows more thorough rinsing and drainage, therebyreducing the dragout of solutions.

Still further, the invention contemplates, the

provision of a substantially homogeneous, resinous,ribbonlike tape which has relatively hightento be protected without" tearing or breaking.

Still further, the invention contemplates the I provision of a, protective tapewhich, while relatively smooth and glossy in appearanceand while .20

not tacky or sticky to touch, eflfectively and sticks to itseli when. tightly wrapped I thearticles to be protected,

z w eres Many other and further objects, advantages,

"andieatu resof the. presentinvention will be.-

tape which is preferably of considerably thinner dimension in its side marginal edge portions than it is in its central portion whereby to provide a sort of feather edge structure which is particularly effective in obtaining a tight seal with respect to the article to which the tape is applied. Generally speaking. rubber and rubberlike ma-, it

terials have been widely used as protective coatings in operations of this general character and. have been widely usedior this purpose. However, it has been found that protective coatings formed in accordance with the te'achings of the present invention are considerably easier to apply, provide a tighter seal and not only have physical characteristics substantiallyequivalent to those of rubber, but at the same time have very superior chemical characteristics when intended for use in a wide variety of baths or solutions. v a l The coating structure formedin accordance come rnore clearly apparentzl'from the following specification, the drawings relating thereto, and iromthe claims hereinafter set forth. a a

, In the drawings:

Figure 1 illustratcsa fragmentary, portion of the plating rack havingportions thereof protec't ed by the application of the improved electro lytic tape in accordance with the teachings of thezpresent invention;

Figure 2 illustrates tape formed in accordance with the teachingsoi' thepresent' inventionflllustrating the preferable cross-sectional, configuration of the improved with the teachings of the present invention offers 7 effective resistance and complete protection when used in conventional plating solutions throughout all operating temperature ranges.

This is particularly important when the coatings of the present invention are applied to. plating;

racks or used as masking for articles being plated,

inasmuch as the racks and the articles may be exposed to extremely hot cleaning and pickling solutions, as well as to plating baths which may coating material. a

With more particular reierenceto the drawing, it 1 will bereadilyappreciated that in order to be effective for the purpose intended, tape of the general character to whichthe present invention relates must be relatively flexible. elastic, and be capable of substantial adherence to itself or to the articles being covered without being suiflciently gummy or tajckyto prevent satisfactory handling. a

which the-tape of the present invention is formed and its mannerof fabrication constitute important features of the present invention.

While many of the advantageous features of the present invention may be employed by the substitution of various other resinous materials,

highly, alkaline in perspective a roll of the tape as produced Iorproviding such coatings.-

Figure 3 is an enlarged cross-sectional viewroi Consequently, the material from for the specific composition hereinafter set forth. it has been found preferably to produce the tape of the present invention by extrusion of an appropriate mixture of resinous material through a conventional extrusion die into an appropriate bath of coagulating fluid. Such extrusion operations are well known and any conventional method may be employed.

The improved tape is preferably formed of a copolymer of two different vinyl compounds, by which is meant the conjoint polymerization of two or more compounds while in mutual contact. One of these compounds comprises a vinyl halide such as vinyl chloride, for example, or vinyl benzene (styrene), this compound being generally known as "hard resin, and the other compound such as vinyl acetate, vinyl propionate, or vinyl butyrate, for example, generally referred to, when separately polymerized, as "soft resin.

When two such resins are c'onjointly polymerized and the resultant product extruded to form comprising a generally homogeneous resinous ribis preferably an ester of a lower aliphatic acid vinyl compound of the hard resin-forming type,

and 50 to 5 parts of the vinyl ester of the "soft resin-forming type, it being found preferable to utilize as a general rule approximately 93 to 95' parts of hard" forming type resin and 7 to 5 parts of soft forming type resin,

When appropriate proportions of these two types of resins are copolymerized and extruded through an extrusion die to provide a cross-sectional configuration to that shown in Figure 3 of the drawing, a particularly satisfactory product results. The resultant product has a generally lossy appearing finish andis not sticky or tacky to handle, is easily and conveniently applied to plating racks or parts to be plated, and provides a particularly effective coating covering. This is particularly true because of the fact that the tape has a'relatively high tensile strength and considerable resilience and, therefore, can be tightly wrapped around and engage the surface of the parts'to be protected to provide a protective coating and at the same time effectively adhering to itself in order to provide a substantially continuous coating over the surface to which the tape is applied.

While not essential to provide an adequate protective covering, it is in some instances desirable to bake or heat-treat the wrapped coating after the same has been applied. This baking serves to fuse adjacent portions of the tape together and to a certain extent provide a tighter and more effective seal.

While the particular dimensions of the crosssectional configuration of the tape may be varied throughout a relatively wide range and yet at the same time obtain satisfactory results, it has been bon-like strip having a generally glossy surface adherent to itself but yet capable of satisfactory handling and having a tensile strength sufllcient for tight wrapping of the tape without breaking or tearing, said tape being of substantially greater thickness in its central portion than at its marginal edges whereby, when applied to and maintained under tension on an article to be treated and subsequently heat treated, there results a fusing together of adjacent portions of the tape in order 'to provide a tight and effective seal while retaining the tensile strength in the thicker portion of the tape. I

2. An electrolytic protective flexible elastic tape comprising a generally homogeneous resinous ribbon-like strip having a generally glossy surface adherent to itself but yet capable of satisfactory handling and having a'tensile strength sufllcient for tight wrapping of the tape without breaking or tearing, said tape being of maximum thickness in its central portion and tapering to substantially a feather edge at its marginal edges whereby, when applied to and maintained under tension on an article to be treated and subsequently heat treated, there results a fusing together of adjacent portions of the tape in'order' to provide a tight and effective seal while retaining the tensile strength in the thicker portion of the tape.

3. An electrolytic protective flexible elastic tape comprising a generally homogeneous resinous ribbon-like strip-having a generally glossy surface adh'erent to itself but yet capable of satisfactory handling and having a tensile strength suiilcient for tight wrapping of the tape without breaking or tearing, said tape being of maximum thickness in its central portion and gradually tapering to a substantially reduced thickness at its marginal edge portions whereby, when applied to and maintained under tension on an article to be treated and subsequently heat treated, there results a fusing together of adjacent portions of the tape in order to provide a tight and effective seal while retaining the tensile strength in the thicker portion of the tape.

- 'ORVIS H. LEIDY.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,357,350 Schumacher Nov. 2, 1920 2,105,728 Geller Jan. 18, 1938 2,101,876 Scott Dec. 14, 1937 OTHER REFERENCES Pamphlet, Vinylite Resins, Carbide and Carbon Chemicals Corp,, May 1, 1937, page 6. Division 50.)

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